Improvement in metal-bending machines



E W. STEW ART.

Metal-Bending Machine.

No. 220,503. Patented Oct. 14,1879.

ITNESSES *NVENTOR wm W M ATTORN EY PL FEIERS, PHOTO-LITHOGRAFHER. wq n umstom 0 C UNITED STATES PATENT OEEIoE.

ENOS W. STEWART, OF KALAMAZOO, MICHIGAN, ASSIGNOR OF ONE-HALF OF HIS RIGHT TO JOHN H. ROLSON, OF SAME PLACE.

IMPROVEMENT IN METAL- BENDING MACHINES.

Specification forming part of Letters Patent No. 220,503, dated October 14, 1879; application filed May 9,1879.

, To all whom it may concern:

State of Michigan, have invented certain new and useful Improvements in Metal-Bending Machines; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a partof this specification.

The object of this invention is to furnish a convenient machine for bending bars of metal into angular forms, and especially into the double-crank form usual in sulky-plow axles, without weakening said bars thereby. This object is attained by the construction, combination, and arrangement of devices hereinafter particularly set forth and claimed.

In the accompanying drawings, Figure 1 represents a top view of my metal-bending machine in horizontal position, ready to be secured to a bench or other support for use. Fig. 2 represents a front-edge view of the same; and Fig. 3 represents a detail view of the clamping-lever, showing the grooves on the terminal operating portion of the same.

A designates the bed-plate of my machine, which is secured to a work-bench or other convenient support in a horizontal position. This plate is semicircularly-recessed in its front right-hand corner at a to receive the circular head B of bending-lever B, which has for its fulcrum pivot rod or bolt b. This pivot-bolt is arranged centrally with reference to circular lever-head B and recess a of bed-plate A, and is attached to bearing-plates A A which are secured, respectively, to the top and to the bottom of bed-plate A. The metal of said bed-plate surrounding recess a serves to guide head B and brace pivot-bolt b. The front part, B, of lever B is provided with a shoulder which has an inclined end, b and the proximate front part of bed-plate A has a similar incline, a. These inclined parts a b engage witheach other when lever B is turned at right angles with the front of plate A, and prevent said lever from turning beyond this rectangular position. When attached to a workbench for use all the working parts of the machine extend forward beyond the bench.

The top of bed-plate A is provided with longitudinal guide-bar O and angular guide-bar D, which are separated by a transverse passage or supplementary guideway, F. This guideway F is extended in the same transverse direction by means of the grooved outer side of the transverse arm cl of angular guide-bar D. The longitudinal arm d of said angular guide-bar and the guide-bar O are also similarly grooved on the outer faces. The form and size of the groove are such in each case that it will readily receive the metallic rod to be bent when said rod is laid along the face of the guide-bar. Longitudinal arm at of angular guide-bar D extends under top bearing A and braces lever B against vertical strain. Its outer end is recessed to allow the movement of the proximate rounded end of a third guide-bar, E, which is firmly attached to or formed on the upper face of bending-lever B. The front of this guide-bar E is longitudinally grooved in continuation of the groove in the front of guide-bars O D. When lever B is drawn forward the continuity of this guidegroove is not broken thereby, but its shape becomes more and more removed from a straight line, until at last it is a right angle.

It is obvious that if a straight bar of metal be clamped immovably to this guideway durin g the turning of lever B, said bar will be grad ually bent into the shape of a right angle.

The devices which I employ to effect this clamping are a horizontally-operating clamping-lever, Gr, and a vertically-operating lockin glever, H. The former (shown in detail in Fig. 3) is pivoted on the top of lever B, and has a square terminal operating part, which is pro vided with a groove, g, similar to the guideway grooves already described, and running along both the end and the rear of said lever Gr.

Clamping-lever G is held tightly against the bar to be bent as the weight of the long end of locking-lever H forces upward the short end of said lever and causes the pin h, carried there by, to pass up through a hole in lever B and be hind clamping-lever Gr. By raising the long end of locking-lever H pin h is withdrawn and clamping-leverGis sctfree. When said clamping-lever is turned to grasp a bar of metal it is not necessary to operate locking-lever H to get pin 71. out of the way, as the tip of said pin is beveled outwardly, so that the said clampinglever coming in contact with the incline on the pin it automatically forces said pin back out of the way.

To prevent longitudinal extension of the bar to be bent and to more perfectly secure it, I em ploy stop-blocksIJ, which extend into the main guideway at the ends thereof, and are longitudinally adjustable respectively in slot 1' of plate A and slot j of lever B by means of suitable clamping devices. This adjustability adapts the machine to use with bars of different lengths. When the bar is clamped to the guideway by the lever (l, and bent as stated, it is evident that it will not be weakened in the bend; but, on the contrary, it will be strengthened, since the shortening of the guideway will force a greater amountof material into the same Space, and longitudinal expansion will be prevented, while the tight fit of the clamping end of lever G will prevent any change of shape in the cross-section of the bar. The corner of the terminal part of lever G corresponds so exactly with the angle formed by the guidcway when bent forward as far as possible, as before described, that a perfect right angle in the bent bar is thereby insured.

To make a second bend, as for a sulkyplow axle, one part of the bent baris clamped in the main groove as before, the other part extend- 'mg transversely through supplemental guideway F. The operation of bending is then repeated.

It is obvious that the clamping devices and other parts of the machine may be considerabl y changed without departing from the spirit and scope of my invention.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In combination with the bending-lever and clamping device, fixed guide-bars C D, movable guide-bar E, and supplemental transverse guideway F, substantially as and for the purpose set forth.

2. The combination of adj ustable stop-blocks I J, slotted bed-plate A, and slotted lever B with guide-bars and clamping devices, substantially as set forth.

3. The combination, with fixed guide-bar D and bending-lever B, of clampin g-lever G, lockin g-lever H, and beveled pin h, said pin being thrown upward by the weight of the long arm of lever H and automatically forced back by lever G during its closing movement.

4. In combination with bending-lever B, guide-bars (J D E, and clamping-lever G, the end stop-blocks I J, arranged substantially as set forth.

In testimony that I claim the foregoing as my own I afiix my signature in presence of two witnesses.

ENOS W. STEWART.

Witnesses OSCAR TUTHELL, JOHN H. RoLsoN. 

